1. Field of the Invention
This invention relates to a method and a device for coupling a cassette supported typewheel to a typewheel positioning shaft in electronically controlled typewriters or similar machines.
2. Description of Prior Art
Typewriters or printers have become known in which a cassette supported typewheel and a typewheel positioning shaft are coupled automatically after the cassette has been inserted into an appropriate seating device. For instance, the U.S. Pat. No. 4,127,335 shows such a device which, however, requires considerable mechanical sophistication. To equip a machine with this known device means a high machine price. The situation is similar for an arrangement according to DE-OS 29 37 678 which also necessitates unjustifiably high costs to be able to couple the typewheel to the typewheel positioning shaft. Other devices, e.g. according to DE-OS 32 11 402, show mechanisms in which the typewheel must be arrested prior to the actual coupling process. This also requires a corresponding mechanical sophistication. The cassette supported typewheel mounting scheme in European Pat. No. 13 346 also is disadvantageous in that the cassette mounted typewheel cannot be turned when the cassette is removed from the machine. This means that before the cassette with the typewheel is removed from the machine a routing program must be run to assure that the typewheel is in a predetermined, defined basic position in the cassette in order to be fixed unturnably in the cassette. When inserting the cassette into the machine, a motion cycle must be run which sees to it that the typewheel can be turned in the cassette.
All of these known devices have the disadvantage of not inconsiderable costs for mechanical parts, resulting in increased production and assembly costs. Also, in some, programs must be run which also have an unfavorable effect on costs or take time.